Ćulafić, Lj., Grubišić, D., Nešković, M. 1978-1980 (1982): Endogenous gibberellin-like substances and inhibitors in callus tissue of Spinacia oleracea L. - Endogeni giberelini i inhibitori u kalusnom tkivu Spinacia oleracea L.- Glasn. Inst. Bot. Bašte Univ. Beograd 13-15(1-3): 29-35.